Not sure what exactly you mean.
Formloom 4 is a plug-in, so if you’re looking for a “stack” in the stacks library you won’t find it there. You’ll need to add a Formloom page just like you add a stacks page.

Once you’ve setup the form on the Formloom page you can use the provided stack to display it on a stacks page. You do need to follow the instructions on the Formloom documentation page.